The present invention relates to medical devices. More particularly, the present invention relates to embolic protection devices and methods for capturing emboli within a body vessel.
Presently, there are a number of treatments for embolic protection to prevent emboli and blood clots from traveling within the vasculature that create undesirable medical conditions, such as ischemic stroke, brain aneurysm, and pulmonary embolism. For example, vena cava filters are commonly employed to trap blood clots and emboli in the vena cava filter to prevent pulmonary embolism; snares and baskets (for example, stone retrieval baskets) are generally employed to retrieve urinary calculi; and occlusion coils are typically employed to occlude aneurysms and accumulate thrombi in a body vessel.
Treatments for stenotic lesions create a potential in releasing blood clots and other thrombi plaque in the vasculature of the patient, for example, in the treatment for carotid artery stenosis. Generally, carotid artery stenosis (also called carotid artery disease) is the narrowing of the carotid arteries, which are the main arteries in the neck that supply blood to the brain, usually caused by plaque build-up in the carotid artery, creating a relatively high risk factor for ischemic stroke. Plaque forms when cholesterol, fat and other substances form in the inner lining of an artery. This formation process is know as atherosclerosis.
Depending on the degree of stenosis and the patient's overall condition, carotid artery stenosis has been treated with surgery. This procedure, known as carotid endarterectomy, removes the plaque from the arterial walls. Carotid endarterectomy has been shown to benefit patients with arteries that are substantially narrowed, for example, by about 70% or more. For people with arteries that are not as narrowed, for example, less than about 50%, an anti-clotting drug, such as anti-platelet agents and anticoagulants, may be prescribed to reduce the risk of ischemic stroke.
Carotid angioplasty is a more recently developed treatment for carotid artery stenosis. This treatment uses balloons with or without stents to open a narrowed artery. This procedure can be performed through a standard percutaneous transfemoral approach with the patient anesthetized using light intravenous sedation. At the stenosis area, an angioplasty balloon is delivered to predilate the stenosis in preparation for placement of a stent. The balloon is then removed and exchanged through a catheter for a stent delivery device. Once in position, a stent is deployed across the stenotic area. If needed, another balloon can be placed inside the deployed stent for post-dilation to ensure that the struts of the stent are pressed firmly against the inner surface of the vessel wall.
During the stenosis procedure, there is a risk of blood clots and thrombi being undesirably released into the blood flow within the vasculature. Embolic or distal protection devices have been implemented to capture emboli. However, many current embolic protection devices restrict flow when deployed within the vasculature of the patient. Moreover, many embolic protection devices are relatively difficult to collapse and retrieve after the need for such a device in the vasculature passes.
In view of the above, it is apparent that there exists a need for an improved device and method for distally protecting and capturing emboli within a body lumen during a stenosis procedure.